The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 26, 1996
Filed:
Oct. 27, 1995
Ryuji Sato, Wako, JP;
Kojiro Tsutsumi, Wako, JP;
Toshitaka Hachiro, Wako, JP;
Hiroshi Kawaguchi, Wako, JP;
Sachito Fujimoto, Wako, JP;
Honda Giken Kogyo Kabushiki Kaisha, Tokyo, JP;
Abstract
An air-fuel ratio sensor deterioration-detecting system for an internal combustion engine includes a catalytic converter arranged in the exhaust system, first and second air-fuel ratio sensors arranged in the exhaust system at respective locations upstream and downstream of the catalytic converter, and an ECU which calculates a value of a first control parameter, based on an output from the second air-fuel ratio sensor, and executes air-fuel ratio feedback control, based on the calculated value of the first control parameter. A value of a second control parameter to be used for calculating the value of the first control parameter is calculated based on the output from the second air-fuel ratio sensor. Whether the second air-fuel ratio sensor is deteriorated is determined based on the output from the second air-fuel ratio sensor. A value of at least one of the first and second control parameters is increased when a variation in the output from the second air-fuel ratio sensor is small during execution of the air-fuel ratio feedback control, and it is determined that the second air-fuel ratio sensor is deteriorated when the variation in the output from the second air-fuel ratio sensor is continuously small over a predetermined time period after the value of the at least one of the first and second control parameters has been increased.